The orchid flora of Namibia is depauperate and as a result is poorly studied.

Objectives

To further document the orchid flora of Namibia.

Method

New herbarium collections were studied and the relevant published literature consulted.

Results

Habenaria kilimanjari is newly recorded for Namibia.

Conclusion

The newly recorded species increases our understanding of the orchid diversity in Namibia and underlines the need for continued botanical inventory work.

The orchid flora of Namibia is depauperate compared to the rest of sub-Saharan Africa because most of the country is arid and thus not good habitat for orchids. Despite this, new country records are occasionally discovered (Bytebier 2013). The wetter, more suitable habitats are found in the Caprivi Strip, but they are difficult to access during the wet season and are therefore less well explored.

In the course of 2015, the second author collected an orchid specimen (Mannheimer 4850, Figure 1a) of which the identity could not be established immediately and which was therefore sent by the Windhoek Herbarium (WIND) to the first author for identification.

FIGURE 1

Habenaria kilimanjari in situ.

Close examination of the plant and the accompanying photographs showed that this specimen belongs to the genus Habenaria, but is a taxon that has not been recorded in South Africa (Johnson & Bytebier 2015) or Namibia. With the help of the keys in the Flora of Tropical East Africa (Summerhayes 1968) and Flora Zambesiaca (La Croix & Cribb 1995), its identity was established as Habenaria kilimanjari Rchb.f., previously only recorded from Angola, D.R. Congo, Kenya, Malawi, Tanzania and Zambia (WCSP 2016).

The dissected flowers of the specimen closely match the drawings made by Summerhayes on the holotype sheet of H. kilimanjari (New s.n.) lodged at K and downloaded from JSTOR Plant Science. The white flowers, which are not common in Habenaria, and the pincer-like ends of the rostellum arms make this a fairly easy species to identify. Furthermore, the first author is familiar with the species as he collected it before in Shimba Hills National Park in Kenya (Bytebier 3160, 24/7/2008, NU, BR; see Figure 1b).

Habenaria kilimanjari is usually found in ‘periodically flooded grassland, often with scattered bushes’ (Summerhayes 1968). This particular specimen was found in a seasonally inundated depression.